Microstructural Development of Ti-35Nb-TiC Metal Matrix Composites

Metal matrix composites (MMCs) have received considerable attention due to their low density with good elastic modulus and high strength to weight ratio. Discontinuous reinforced Ti matrix composites have been found as a promising material for applications in various fields, such as aerospace, automotive, biomedical and advanced military applications, because of their low cost, improved performance and ease of fabrication. Among the discontinuous ceramic reinforcements, TiC is identified as a very suitable reinforcement for the Ti system because of its excellent properties and high compatibility with Ti matrices. In this study, investigations have been conducted on the influence of volumetric percentage of TiC (10%) on microstructural development of TiC reinforced titanium beta matrix composite prepared by the blended elemental method from hydrided powders using ex situ processing route. Samples were produced by mixing of elemental hydrided powders followed by uniaxial and cold isostatic pressing with subsequent densification by sintering (900°C- 1500°C), in high vacuum. Sintered samples were characterized for phase composition, microstructure, microhardness and mechanical properties by X-ray diffraction, scanning electron microscopy, Vickers indentation, respectively. Density was measured by Archimedes method. The experiment results revealed that TiC content has significant influence on the microstructure and improving the hardness values of Ti-35Nb-TiC composites. A homogeneous distribution of TiC particles was observed, with a reduced presence of agglomerates and macroporosities. There was an increase of 28.5 % in the hardness of the composites with the addiction of TiC, which indicates the possibility of using components manufactured using this technique, for example, in aircraft landing gears that are subject to high mechanical stress and orthopedic implants.